1. Technical Field
The present invention relates generally to connection assemblies for mounting modular-type carrier structures upon a transporting vehicle. In an exemplary embodiment utilized herein for illustrative purposes, the article to be connected to the transporting vehicle is a load carrier designed for transporting sports equipment such as bicycles on a motor vehicle. In the disclosed assembly, a unique modular hitch mount connection is utilized that provides wobble-free interconnection between the load carrier and the receiving mount on the vehicle.
2. Background Art
Attachment of a carrier frame behind a vehicle to transport equipment, especially sports equipment such as bicycles, is well known. A problem with carrier frames, attached to vehicles, occurs when encountering rough terrain during a journey. Since most carrier frames have interconnected modular parts, including the connection to a vehicular mounted hitch receiver, the opportunity exists for the occurrence of play or wobble between parts. Depending on the extent of such play or wobble, the load carrier frame may permit or generate movement that causes equipment supported on the carrier to collide with the load carrier frame, its support structure, or the rear of the vehicle. The result of such a failure to control the relative movement of the components can be damage to the sports equipment or to the vehicle itself. Therefore, it becomes important to minimize any wobble or play associated with the load carrier frame and its connection to the carrying vehicle.
U.S. Pat. No. 5,244,133 provides a description of a wobble-free trailer hitch mounting. The mounting fits inside the receiving opening of a receiver type hitch. At least a portion of the mounting responds to the rotation of a threaded rod to enlarge the effective width of the mounting. When positioned inside the receiving hitch, as its effective width increases, the mounting exerts pressure on the inner walls of the receiving hitch and this limits play between the mounting and the receiving hitch to meet the requirement that the connection be wobble-free. The mounting of the ""133 patent, however, includes multiple parts and a relatively complex mechanism to increase the effective width of a portion of the mounting to exert wobble free gripping action against the receiving hitch.
U.S. Pat. No. 5,820,004 also describes an anti-wobble connector to remove play or wobble that might occur between the load carrier and transporting vehicle. The anti-wobble connector of the ""004 patent includes several relatively small parts that may easily be lost. The tension required to preclude wobble and remove play in the interconnection is concentrated upon an entry surface of the hitch receiver in such a manner that the force required to limit undesirable movement is localized in a relatively small region of the connection between the anti-wobble connector and the receiving hitch. These concentrated forces can result in high levels of stress in the component parts.
In view of the above described deficiencies associated with the use of known designs for anti-wobble connections, especially in hitch mounted load carriers, the present invention has been developed to alleviate these drawbacks and provide further benefits to the user. These enhancements and benefits are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.
The present invention in its several disclosed embodiments alleviates the drawbacks described above with respect to conventionally designed modular hitch mount connections and incorporates several additionally beneficial features. A noticeable beneficial feature of the current invention is the simplicity of the mechanism for removing play or wobble between parts of the connection. The elegance of the design is obvious in the illustrated embodiment in which an appropriate wobble-free securement is accomplished utilizing a pair of strategically located nuts positioned at an angle of 90xc2x0 to each other on internal surfaces of a tubular section of the assembly referred to herein as a support tube. Access orifices, formed in the support tube adjacent the nuts provide entry access for coupling bolts to be installed therein.
Formation of the modular hitch mount connection of the invention requires insertion of the support tube into a mounting member, described herein as a tubular seat. The access orifices in the support tube become aligned with mounting holes in the tubular seat when the support tube is inserted correctly into the seat. Correct alignment of the parts facilitates formation of a connection between them using a pair of coupling bolts. The first coupling bolt passes through the openings in the tubular seat and the support tube and extends across the width of the combined tubes for ultimate engagement with the nut that is secured to the internal surface of the support tube. Rotation of the engaged bolt draws the head of the bolt into contact with the outer surface of the tubular seat and upon continued rotation, the tubular seat makes firm contact with the outer surface of the support bar. In this manner, the first coupling bolt connects the tubular seat to the support bar and limits movement between them. A second coupling bolt is inserted through orifices located at a different horizontal level and at 90xc2x0 to the first coupling bolt on an adjacent face of the support as is illustrated. The second coupling bolt engages a second nut that is similarly secured to the inside of the support tube in alignment with the second set of orifices. Rotation of this second coupling bolt affects a similar connection and limitation of movement between the tubular seat and the support tube. The now fully formed modular hitch mount connection of the invention provides a tightened structure with two primary connecting forces operating at 90xc2x0 to one another to draw the support bar into solid, wobble-free contact with the tubular seat. The area of contact involves longitudinal surfaces extending the full length of the portion of the support tube positioned inside the tubular seat.
The modular hitch mount connection of the present invention possesses an additional beneficial feature related to its efficient use of a minimized number of parts. Essentially, only the coupling bolts represent components that are loosenable from the primary load carrier structure. A lost bolt will be easy to replace, since the connection is designed to utilize standard coupling bolts of a common, standard size. Because the current invention uses a dual bolt connection system, the loss of one bolt does not prevent formation of a suitable connection, albeit less rigid. This contrasts with designs in the prior art where loss of a part essentially disables the connection mechanism.
In at least one embodiment of the present invention, a modular hitch mount connection is provided for attaching a tubular carrier structure to a load arm inserted in the receiving tube of a receptacle-type hitch. The modular hitch mount connection includes a tubular seat having an open end, and a first wall joined at an angle of 90xc2x0 to a second wall. The first wall and the second wall each have at least one hole formed therein. A support tube is included that has a proximate end and a distal end with respect to the tubular seat. The proximate end is sized to slidably engage the tubular seat at the open end of the seat. The support tube also has an inner surface and a first sidewall disposed at 90xc2x0 to a second sidewall. Like the tubular seat, the first sidewall and the second sidewall of the support tube each have at least one orifice formed therein. When properly assembled, the first wall of the tubular seat is located adjacent the first sidewall of the support tube with the hole in the first wall axially alignment with the orifice in the first sidewall. Similarly, the second wall of the tubular seat is located adjacent the second sidewall of the support tube when assembled with the hole of the second wall in axial alignment with the orifice of the second sidewall. Two threaded nuts are secured upon the inner surfaces of the support tube in axial alignment, one each with the orifices through the first and second sidewalls. Two cross-oriented tensioning bolts are inserted and screwably engaged, one each, into the threaded nuts for securing the support tube to the tubular seat. Upon continued rotation and ultimately tightening of the tensioning bolts, movement of the support tube relative to the tubular seat is prevented by the resulting solid and pressing contact between the first wall and the first sidewall and the second wall and the second sidewall.
The beneficial effects described above apply generally to the exemplary devices and mechanisms disclosed herein for a secure and play-reduced modular hitch mount connection typically for utilization in the mounting of a load carrier to a transporting vehicle. The specific structures through which these benefits are delivered will be described in detail hereinbelow.